I've had a Eljer 1.6 gal flush toilet now for 5+ years, and it works perfectly fine.
In fact, I'll be getting two NEW 1.6 or the new 0.8 (I think) gal flush toilets next week, upon the completion of the remodeling project.
I see no issues with using a water saving toilet, provided that you use a decent one, not an el cheapo one. Think of 5w-20, you want to use a good one.
If I have time later, I'll scan a copy of my Consumer Report's Toilet Reviews.